1. Field
Methods and apparatuses consistent with exemplary embodiments relate to a magnetic resonance imaging (MRI) acoustic system, and more particularly, to an MRI acoustic system including an acoustic output device and an electro-acoustic transducer that operate based on a magnetic field of the MRI acoustic system.
2. Description of the Related Art
A magnetic resonance (MR) image is obtained through magnetic resonance of an atomic nucleus in a magnetic field. Resonance of an atomic nucleus is a phenomenon where the atomic nucleus in a lower energy state changes to a higher energy state by absorbing high frequency energy when specific high frequency energy is irradiated to the atomic nucleus that is in a magnetized state due to an external magnetic field. Atomic nucleuses have different resonance frequencies according to their types, and the resonance is affected by the intensity of the external magnetic field. There are a large number of atomic nucleuses in the human body, and generally, a hydrogen atomic nucleus is used for MRI.
An MRI apparatus is non-invasive, has a superior tissue contrast compared to the computed tomography (CT), and generates no artifacts due to bone structure. The MRI apparatus may take various cross-sectional images in desired directions without changing the position of a shooting object. Thus, the MRI apparatus is widely used together with other image imaging apparatuses.
A dynamic speaker, a loud speaker, or a piezo-electric speaker is used as an electro-acoustic transducer for outputting an acoustic signal to a patient undergoing medical diagnosis by using the MRI apparatus.
A loud speaker or a piezo-electric speaker is mainly used as an acoustic outputting device for an MRI apparatus. However, a magnetic material in the loud speaker may affect the magnetic field of the MRI apparatus, and the piezo-electric speaker has a limited number of frequency bands for sound output and is expensive.
There is a need to develop an electro-acoustic transducer and an acoustic output device with the decreased production cost, improved sound quality, consistent low sound generation ability, and lessened degree of effect on the quality of an MRI image.